Draper Expert 1/2" Square Drive Wobble Extension Bar Range - Draper Expert 16754, Expert Quality, manufactured from chrome vanadium steel hardened and tempered with a polished finish. Each ext. bar has a knurled ring for extra grip. Machined wobble end allows sockets to be driven at up to 15° to the vertical. Attached with a spring - loaded ball bearing for secure socket holding. Display packed. Draper Expert 16754 1/2" Sq. Dr. Wobble Extension Bar (50mm)